Acid-Base Reactions and Buffers · 酸碱反应与缓冲溶液
| English | 中文 | Pinyin · 拼音 |
|---|---|---|
| buffer/ˈbʌfə/ | 缓冲溶液 | huǎn chōng róng yè |
A solution that resists change
- Add a drop of strong acid to water and the pH plunges.
- But add it to blood, and the pH barely budges.
- Something in there soaks up the shock.
- That protective mixture is the star of this lesson.
一种抵抗变化的溶液
- 向水里加一滴强酸,pH 骤降。
- 但把它加到血液里,pH 几乎不动。
- 里面有某种东西吸收了这份冲击。
- 那种起保护作用的混合物是本课的主角。
The buffer recipe
- A buffer 缓冲溶液 resists changes in pH.
- It contains a weak acid and its conjugate base together.
- Both partners are present in significant amounts.
缓冲溶液的配方
- 缓冲溶液抵抗 pH 的变化。
- 它同时含有一种弱酸和它的共轭碱。
- 两个搭档都以可观的量存在。
A buffer is made from... · 缓冲溶液由……组成
A buffer pairs a weak acid with its conjugate base. · 缓冲溶液将弱酸与其共轭碱配对。
A working buffer must contain both a weak acid and its conjugate . · 一个有效的缓冲溶液必须同时包含弱酸及其共轭。
Both partners are needed to absorb acid and base. · 两种组分都需要以吸收酸和碱。
Soaking up acid or base
- Add acid, and the conjugate base neutralizes it.
- Add base, and the weak acid neutralizes it.
- Either way, the pH changes only a little.
吸收酸或碱
- 加入酸,共轭碱把它中和。
- 加入碱,弱酸把它中和。
- 无论哪种,pH 都只改变一点点。
When strong acid is added to a buffer, it is neutralized by the... · 当向缓冲溶液中加入强酸时，它会被……中和。
The conjugate base reacts with the added $\text{H}^+$. · 共轭碱与被加入的$\text{H}^+$反应。
When strong base is added to a buffer, it is neutralized by the... · 当向缓冲溶液中加入强碱时，它会被……中和。
The weak acid reacts with the added $\text{OH}^-$. · 弱酸与被加入的$\text{OH}^-$反应。
Keeping systems stable
- Blood is buffered to stay near pH 7.4.
- Many reactions need a steady pH to work.
- A buffer holds that pH against small disturbances.
让系统保持稳定
- 血液被缓冲,保持在 pH 7.4 附近。
- 许多反应需要稳定的 pH 才能进行。
- 缓冲溶液顶住小扰动,守住那个 pH。
Is it a buffer? · 它是缓冲溶液吗？
Sort each mixture by whether it forms a buffer. · 根据每种混合物是否形成缓冲溶液，对其进行排序。
A buffer resists large changes in pH when small amounts of acid or base are added. · 当加入少量酸或碱时，缓冲溶液能抵抗pH的大幅变化。
That resistance is exactly what a buffer does. · 这种抵抗作用正是缓冲溶液的功能。
A buffer holds both acetic acid and acetate. You add a little strong acid. What happens?
- The acetate (the conjugate base) reacts with the added acid.
- So the pH drops only slightly.
一种缓冲溶液同时含有醋酸和醋酸根。你加入少量强酸。会发生什么?
- 醋酸根(共轭碱)与加入的酸反应。
- 所以 pH 只轻微下降。
A buffer can be overwhelmed if enough acid or base is added. · 如果加入足够的酸或碱，缓冲溶液可能会被耗尽（失效）。
Buffers only handle small additions before failing. · 缓冲溶液仅在加入少量物质时才有效，随后会失效。
A buffer needs both a weak acid and its conjugate base present -- a strong acid alone cannot buffer. It only resists small additions; enough acid or base will overwhelm it. And it minimizes the pH change, it does not prevent it entirely.
缓冲溶液需要同时存在一种弱酸和它的共轭碱——单独的强酸不能缓冲。它只抵抗少量的加入;足够多的酸或碱会把它压垮。而且它减小 pH 变化,并不完全阻止它。
A buffer is a weak acid together with its conjugate base, and it resists pH change: the conjugate base neutralizes added acid while the weak acid neutralizes added base. It only softens small disturbances (like keeping blood near pH 7.4), and can be overwhelmed.
缓冲溶液是弱酸连同它的共轭碱,它抵抗 pH 变化:共轭碱中和加入的酸,而弱酸中和加入的碱。它只减弱小扰动(如让血液保持在 pH 7.4 附近),且会被压垮。